1. Field of the Invention
The present invention relates to a gesture recognition module and a gesture recognition method, and more particularly, to a gesture recognition module and a gesture recognition method capable of recognizing a back-and-forth gesture of a hand accurately.
2. Description of the Prior Art
With the progress and spread of a high-speed network, a user can watch digital contents and multimedia information via a computer or a set-top box. In general, the user needs to input a command to the computer or the set-top box via an input device such as a keyboard, a mouse, etc., to control the computer or the set-top box, e.g., select or display the digital contents and the multimedia information. That is, it is difficult to control the computer or the set-top box, if the user does not (or is not inconvenient to) use the abovementioned input devices. Thus, convenience of the computer or the set-top box is limited.
On the other hand, as technology of image recognition becomes more and more mature, gaming devices with the image recognition are provided by video game manufacturers, peripheral devices with the image recognition are provided by computer manufacturers and liquid crystal display (LCD) televisions (TVs) with the image recognition are provided by appliance manufacturers. Thus, the user can control a gaming device, a peripheral device or a LCD TV via the image recognition. Among various types of the image recognition, one of widely used image recognition is gesture recognition. When controlling an abovementioned device via the gesture recognition, the user needs to make a predetermined gesture in front of a detector (e.g., camera) coupled to the device. Then, the device can determine (i.e., recognize) a command inputted by the user, and execute an operation corresponding to the command.
However, accuracy of the gesture recognition is easily affected by the position of the user. For example, when the user wants to control a LCD TV via the image recognition, a detector of the LCD TV detects gestures of the user for determining commands that the user wants to perform, so as to make the LCD TV to execute corresponding operations. When the user stands directly in front of the detector and faces the LCD TV, the LCD TV can accurately determines the gestures of the user, especially three-dimensional (3D) gestures (e.g. pushing forward gesture or pulling back gesture), through detecting the positions of the hand before and after the hand moves (e.g. the variations of the positions of the hand in top-and-bottom direction (Y-axis), left-and-right direction (X-axis) or back-and-forth direction (Z-axis)). When the user stands obliquely in front of the detector or obliquely faces the LCD TV, the detector detects variation of the positions of the hand in the back-and-forth direction (Z-axis) even the gesture of the user is a lateral gesture (i.e. the hand moves in X-axis and/or Y-axis) instead of the back-and-forth gesture. In such a condition, the detector would erroneously decide the gesture is the back-and-forth gesture and executes inappropriate operations or does not execute any operation. Although an image recognition algorithm with a higher complexity or the detector with a higher cost can be used to improve the accuracy of the gesture recognition, manufacturing cost increases accordingly and sales of the products may be degraded. Thus, improving the accuracy of the gesture recognition with a lower cost is a topic to be discussed and addressed.